Won't start. Dephaser?

[Peca]

Have had Clio Sport 172 for just 2 months and already having troubles with it..

First of all, I already bought it with a knocking sound, which could be heard after warm up and would go away above +/- 2000 rpm. Was told by Renault it won't cause any problems, just makes the noise..
Then I started having troubles with warm starts...I always had to give it some gas to prevent it from stalling. Also it didn't wanna rev above 2000rpm after start up, but once I got it above 2k and revved it some more, it became OK and would idle normally. I was curious anyway what was causing it so I took it to Renault for diagostics. They told me it could be the dephaser and also that I have very high fuel pressure (3,5 bar). On the way back from the service it stalled couple of times when put to neutral. The next day it started, but stalled on the wirst crossroad, and won't start since. First couple of tries it fired up but stalled even with full gas and now it won't start at all, just turns over...

So what is your guess guys, can the dephaser really cause this?

All help is much appreciated. And sorry for my english

 

[TimR26]

Sounds like the crank sensor, try cleaning it as it gets caked in clutch dust. Remove the airbox and you'll see a t-shaped sensor held by two bolts to side of the engine.

 

[sideways danny]

dephaser would cause the noise, but not the other symptoms

I'd suspect the crank sensor, but i'd get it on diagnostics and give it a thorough check

3.5bar fuel pressure is correct BTW, they're clearly idiots

 

[Peca]

Checked the crank sensor...didn't look too bad, cleaned it anyway (I assume only the tip needs to be cleaned), no change...

Here is what they found during diagnostics:
Stored codes were:
Intake air temperature sensor circuit
Back lambda-sensor circuit

They also meassured emissions and said they were off the charts, probably due the "high fuel pressure" (told me the correct value is 3 bars)...which could cause the second fault code..

They think the cause is the dephaser...when it gets really bad, it can get "stuck" in one position which causes the engine to overflow with fuel when starting or something like that (?)

 

[TimR26]

I'd take Danny's advice and get it on a diagnostic. It might still be the crank sensor as cleaning mine only delayed the problem for a couple of months.

 

[sideways danny]

Checked the crank sensor...didn't look too bad, cleaned it anyway (I assume only the tip needs to be cleaned), no change...

There's nothing visible that you'll find wrong with it.

Here is what they found during diagnostics:
Stored codes were:
Intake air temperature sensor circuit
Back lambda-sensor circuit

They also meassured emissions and said they were off the charts, probably due the "high fuel pressure" (told me the correct value is 3 bars)...which could cause the second fault code..

Nice to see Renault know how their own cars work :dead:

"back Lambda sensor" is in simple terms, only there to tell you if the cat develops a fault

They think the cause is the dephaser...when it gets really bad, it can get "stuck" in one position which causes the engine to overflow with fuel when starting or something like that (?)

absolute utter b****cks.

 

[Peca]

SW danny: So, can't it be the cat failure?

 

[Peca]

I'd take Danny's advice and get it on a diagnostic. It might still be the crank sensor as cleaning mine only delayed the problem for a couple of months.

It was on diagnostics, I posted the results above...

 

[caister]

Sounds like they are talking b****cks to me. Do you have another Renault garage you can use? Where do you live?

 

[Peca]

Sounds like they are talking b****cks to me. Do you have another Renault garage you can use? Where do you live?

Brno, Czech republic, only one authorised Renault garage here....

Anyway, what would you suggest? Try swapping the crank sensor? Can the faulty cat cause problems like this?

 

[Peca]

Talked again with the Renault guy and he said that the crank sensor is the first thing they check while doing diagnostics, and that it was ok.
Towing the car over there today to check if it really is the dephaser as they claim..

 

[Peca]

One more thing I remembered. When I was having troubles with the warm starts, it sometimes fell into idle at about 100 rpm after start-up, stayed at 100rpm even with me pressing the gas pedal to the floor, and it took around 20s before it picked up and revved.

 

[Peca]

Well....the bolt on crankshaft pulley was loose...so thats the cause. Hopefully the engine didn't "meet"